For months I have been trying to figure out the best way to download Youtube videos to watch on my iPhone my hour commute to work. I tried a few different methods, the most recent of which was TubeTV. TubeTV was good except it was missing a few key features like continuing partially downloaded files and importing directly into iTunes. I could live with this up until it completely stopped working for me (otherwise I would still be using it).
Enter Tooble. Tooble is the answer. You give it a URL and it downloads the movie, converts it and dumps it straight into iTunes. Great work. Clean and simple.